spinal cord properties

Question 1

how does relative proportion of white and grey matter differ at different levels of spinal cord?

Answer 1

relatively more white matter is present at upper levels of the cord since most of the descending axons destined for inferior levels as well as ascending axons which are heading to the brain from lower levels are represented there.

Question 2

what does blood supply to spinal cord at cervical level begin with?

Answer 2

vertebral arteries

Question 3

what do the vertebral arteries merge to form? what do they do before merging?

Answer 3

the form the basilar artery at the base of the brain stem. before, they give off arterial branches which form the spinal arterial system.

Question 4

what do the vertebral arteries give off?

Answer 4

the anterior spinal artery and the posterior spinal arteries

Question 5

anterior spinal artery

Answer 5

lies in the anterior (ventral) median fissure and supplies the anterior 2/3 of the spinal cord

Question 6

paired posterior spinal arteries

Answer 6

supply posterior 1/3 portion of the cord

Question 7

what do the radicular and segmental arteries do?

Answer 7

they contribute to the spinal cord arterial tree at all levels

Question 8

wherer do radicular and segmental arteries arise from?

Answer 8

spinal branches of vertebral, deep cervical, ascending cervical, posterior intercostal, (and at lower levels from lumbar and sacral arteries)

Question 9

what is the great radicular or great anterior segmental medullary artery?

Answer 9

one of the segmental feeder arteries that is quite large. it usually branches from an inferior intercostal art and contributes very substantially to the anterior spinal artry.

Question 10

what can cause paraplegia?

Answer 10

inadvertent ligation of the ‘great radicular” because it deprives the spinal cord of arterial blood. neural tissue is intolerant of anoxia and even brief loss of oxygenated blood will permanently damage spinal cord neurons, resulting in functional loss.